The alignment of marine propulsion shaft lines is critical to the service life of any marine propulsion system.

Particularly in large vessels, the dynamic behviour of the system, including deflections of massive drive elements and the effects of hull deflection under different seas and load conditions present a complex array of influences on the ideal alignment conditions for the gearbox and stern tube.

The ability to accurately and reliably measure and hence set the relative alignment of the different propulsion system elements is a prerequisite to allow the static propulsion shaft and stern tube alignment setting to be adjusted to the desired position.

Traditional methods of setting a marine propulsion shaft alignment are time consuming and subject to significant uncertainty levels and repeatability errors in their execution. As considerable dock time is consumed in achieving an alignment reading with limited accuracy, in many cases the alignment is subject to further adjustment at sea to improve operating conditions. Subjectively determined adjustments of this nature may be result in the actual shaft and bearing alignment settings being quite individualised and not clearly defined.

The Hamar L700 laser system for marine propulsion systems potentially allows a complete alignment to be done in 30% of the time of traditionl methods and producing highly accurate and reproduceable numerical results.

Briefly described, a datum laser line is adjusted to be precisely on centre to the gearbox output shaft rotational axis, and the position of front and rear stern tube bearings is then directly measured using a self centering target that provides horizontal and vertical offset values at the operator's display unit.

Unique features of the Hamar laser system and the Hamar alignment software allow a fast setup, high stability of the laser readings and provide live alignment readings and graphics that are automatically compensated for mounting errors as well as any desired offsets to the bearing positions.

The potential saving in docking costs alone may readily justify the system cost let alone the improvement in operating conditions that stems from achieving a higher level of shaft and bearing alignment accuracy.

For more information on the Hamar L700 laser system for alignment of marine propulsion shafts, or for a live system demonstration, call IS Tecnik on 02 9546 5676 or email us at: